docs: def list_certs(self, method='all'):
          """List all certificates.
  
          :param string method: The type of certificates to list. Options are
                                'all', 'expired', and 'valid'.
          :returns: A list of dictionaries representing the requested SSL certs.
  
          Example::
  
              # Get all valid SSL certs
              certs = mgr.list_certs(method='valid')
              print certs
  
          """
          ssl = self.client['Account']
          methods = {
              'all': 'getSecurityCertificates',
              'expired': 'getExpiredSecurityCertificates',
              'valid': 'getValidSecurityCertificates'
          }
  
          mask = "mask[id, commonName, validityDays, notes]"
          func = getattr(ssl, methods[method])
          return func(mask=mask)